Mammoth Lakes – Casa Diablo IV Geothermal Plant

February 1, 2013

Residents now have more time to weigh in on what could be one of the biggest infrastructure projects in Mono County’s history.

A brand new geothermal plant that will generate as much power as all three existing Ormat Technologies power plants east of Mammoth Lake is in the works. Last week, the Bishop Bureau of Land Management (BLM) extended the time to comment on the project to Jan. 30.

The 38-megawatt geothermal plant is proposed for a site adjacent to the existing Casa Diablo Road geothermal complex, tucked up against the volcanic bluffs to the east of the complex. The project is in the planning and environmental review phase and is expected to come to fruition several years from now, if it is approved by the federal land agencies on whose land it will sit.

In the meantime, the project is undergoing a federally mandated environmental review process, called a draft Environmental Impact Statement (EIS). BLM extended the public comment period on this draft, originally due on Jan. 15. The comments are now due to the appropriate federal offices (see sidebar) by close of business Wednesday, Jan. 30.

The proposed plant, called the Casa Diablo IV plant, will include as many as 16 new wells and the pipeline to bring the geothermal brine from those wells to the plant. The approximately nine-mile-long pipeline is proposed to run from wells located to the north and east of Mammoth Lakes, including wells near Shady Rest Park.

The prospect of such a large pipeline running though one of Mammoth’s most highly used recreation areas—a pipeline that could be several feet in diameter—has alarmed local recreationists, the Town of Mammoth Lakes, and others, prompting an influx of comments in recent weeks.

The U.S. Forest Service and the state’s Great Basin Unified Air Pollution Control District are cooperating lead agencies for the project

If the project is not delayed significantly, according to Dan Lyster, Mono County’s economic development coordinator, construction could begin on the plant within “the next few years.”

According to Ormat, the project will bring millions of dollars—around $9.1 million—to Mono County, and more during its one-year construction period. Resource extraction projects on federal land, like Casa Diablo IV, pump royalties and money “in lieu of property taxes” into local economies.